Topical wound and burn ointments, creams and sprays are commonly used all over the world. The compositions usually contain wound cleaners, wound healing agents, antimicrobial compounds and so on. Compounds such a hydrocortisone, zinc oxide and antibiotics are common ingredients of such ointments and sprays. Over the counter topical antibiotics, such as neosporin and bacitracin are commonly used to treat skin infections and promote wound healing. Known are also various ointments that contain various natural plant extracts, such as calendula or aloe vera extract. U.S. Pat. No. 5,997,976 for example discloses a burn and wound ointment containing such natural plant extracts.
Bactericidal ointments for the treatment of wounds are well known. Such ointments typically contain an antibiotic or an anti-bacterial agent in an inert vehicle or carrier, such as a paraffin base ointment or an oil-in-water emulsion. U.S. Pat. No. 5,407,670 for example discloses a topical ointment including a mixture of antibiotics to be used for healing epidermal trauma. Also other formulations, such as sprays or foams are known in the art: U.S. patent application Ser. No. 10/639,991 discloses a wound spray for example.
A disadvantage of antibiotic treatment is that bacteria often develop tolerance and resistance to the medication over time, and thus become difficult to eradicate. A prime example is Staphylococcus aureus, which has become resistant to many commonly used antibiotics. As a result antibiotic resistant Staphylococcus-strains are serious problem in hospitals all over the world. Therefore, there is a need for alternative compositions to effectuate healing of wounds and burns and to prevent invasive sepsis.
Recently, novel peptides have been disclosed for antimicrobial purposes. U.S. Pat. No. 5,561,107 discloses a number of amphipatic peptides to treat wounds by stimulating fibroblast and keratinocyte growth in vivo. U.S. Pat. No. 5,955,573 discloses sequences of various lytic peptides and lytic peptide fusion expression vectors.
There is however, a variety of art-recognized problems associated with formulating peptides into pharmaceutically acceptable compositions. It is well known that amphipatic peptides for example are extremely sensitive to their local environment and that it is a great challenge to maintain the activity of peptides in pharmaceutical compositions. Protein aggregation is known to be a source of instability of the peptides and this problem may arise during manufacturing process. Similarly such instability problems may arise during storage. In addition to lowered stability aggregation may result in loss of efficacy, altered pharmacokinetics, as well as unwanted immunogenicity
Accordingly, there is a need to topical formulations comprising active antimicrobial peptides. There is also a clear need for topical antibacterial agent having a large spectrum of activity against bacteria and fungi.
Pursuant to the present invention, healing of burns and wounds as well as prevention invasive bacterial/fungal sepsis in mammals is promoted through the use of a specific composition comprising an effective amount of the antimicrobial peptide disclosed herein.
Other objects and advantages of the present invention will be more fully apparent from the disclosure and claims below.